Gas burner



Patented Jan. 13, 1931 PATENT OFFICE WILLIAM M. HEPBURN, OF TOLEDO, OHIO,

ASSIGNOR TO THE SUBFACE COMBUSTION CO., OF TOLEDO, OHIO, A CORPORATION OF NEW YORK GAS BURNER Application filed April 24,

This invention relates to apparatus for formin and burning self-sustaining mixtures o fuel gas and air and has for its object to provide an apparatus of the character indcated which shall havespecal utility in connection with industrial furnaces. Another object is to provide, in connection with apparatus adapted to form and burn self-sustaining mixtures' of fuel as and air,

a simple and practical means or lighting said mixture which means shall also g be adapted to supply to the furnace a given amount' of heat tending to hold the furnace at a given temperature after the main heatsupplying apparatus has brought the furnace u to temperature. Other objects will more ully appear hereinafter.

Referring to the drawing wherein the preferred form of the invention is shown, the

single figure thereof is an axial section through the burner apparatus which is shown as positioned in the wall of furnace chamber.

In the drawings, 10 indicates the wall of a furnace chamber. The outer face of the wall is recessed to provide a seat for a dished casing 12 within which the major portion of the burner apparatus is housed the casing being substantially closed by a plate 14 having a central opening 16 through which at` mospheric air may reach the burner when a damper or Shutter 18 assocated therewith is open as it normally is when the burner is in operation, the primary purpose of the Shutter being to prevent the entry of air into the furnace when the burner is not in operation. i v

20 indicates a combustion tunnel which opens into the furnace chamber of which the wall .10 forms a part. This tunnel is preferably formed within a body of refrac-- tor material 22 contained within a tubular casng 24 which is removably' positioned within. a suitable 'opening in the furnace wall. The tunnel at its inlet end is provided with a relatively restricted throat 26 which is; of substantial length and preferably of uniform diameter. At the dscharge end of the throat the tunnel is of materially greator diameter and tapers outwardly 1929. Serial No. 857,?07.

whereby the combustible mixture issuing from the throat may have its velocity reduced sufliciently to enable it to burn within the expanding portion of the tunnel.

The self-sustainin mixture of gas and air to be burned in t e tunnel is formed by allowing a jet of fuel gas under relatively hgh pressure to entrain air in two stages, the air entering through the opening 16 in. the casing plate 14 as previ'ously stated. Fuel gas'from a suitable source of supply and under suitable pressure is delivered to a conduit 27 having at its discharge end a jet orifice nozzle 28 from which the gas is jetted across an intervening air space into an entraining tube 30 which in turn discharges across an intervening air space into the throat 26 of the c'ombustion tunnel. The jet. orifice nozzle 28, the tube 30`and throat 26 are of such relative diameters and so positioned with respect to each other that by the time the gas enters the ex anding portion of the combustion tunnel it as entraned sufficient air in passing across said intervening air spaces to form with the air an explosive. or self-sustaining mixture.

The entraining tube 30 and the conduit 27 which carries the gas jet orifice nozzle 28 must of course be supported inrelatively fixed position with respect to the throat 26 1 of the combustion tunnel. This supportin means takes the form of an o en ende body 32 adapted to roject throug an o ening in the bottom oi the casing 12 and orm the mouth of the combustion tunnel. Projecting from the outer face of the body 32 is a spider-like'structure 34 having axally spaced hubs 36 and 38 wherein the conduit t 27. and entraining tube 30 'are respectively supported. For obvious reasons it s' of the first importance that the combustible mixture be not allowed to flow unburned from the combustion tunneL' An 'ordinary li hting pilot is impractical 'because it woul be quic ly snufl'ed out bythe strong draft. The present invention over comes the lighting problem in a 'novel and practicalmanner as will now be explained.

Supported 'by the body 32 is a plurality, preferably a pair, of pilot burners 40 of a 100 type adapted to burn explosive gaseous mixtures, the burners being mounted in cored bosses 42 formed on the opposite inner sloping walls of the body, the burners being supplied with an explosive mixtu'e of fuel gas and air from a supgly conduit 44 which elivers into a distri uting manifold 46 formed in the body. The ex losive mixtre supplied to the conduit is erived from a source of supply exteriorily of the air chamber formed y the casin 12, the mixture being formed by any suita le means not shown..

The pilot burners are cylindrical bodies each having a restricted annular feed passage 48 therethrough formed in. any suitable manner as by a plug of reduced diameter concentrically positioned within the body.

The annular feed passage discharges into a relatively short well formed in the body by having the central plug therein termnate short of the end thereof, the well having an undercut 50. The purpose of the undercut in the well is to cause the combustible mixture which issues from annular feed passage 48 in tubular form to swirl violently within the confies of the well in order that it may start to burn therewithin. The niixture burns at the tip of the burner with a short blow ofl`. The pilot burners are so blue flame which is practically impossible to ostioned as to direct the flame there rom toward the inlet to the throat 26 of the combustion tunnel, the axis of the burners being preferably so positioned that if projected they would intersect at a point adjacent the discharge end of the throat. It is self-evident that the combustible mixture dischar ed into said throat and formed by the jet o gas issuing from the jet orifice 28 will be ignited by the flames from the pilot burners.

The pilot burners serve not only to light the combustible mixture entering the combustion tunnel, but also as auxiliary burners for continuously supplying heat to the furnace chamber of which the wall forms a part after the main burner is shut ofi, the heat i so supplied tending to keep the furnace i t s remembered that after a furnace s chamber up to temperature. The importance of this will be readily appreciated wh'en The inner walls of the dished casing 12 are i mesme provided with heat conducting fins at webs 52 which absorb heat transmtted through the furnace wall. The air entering through the Shutter controlled inlet 16 absorbs heat from the fins 52 and is therefore somewhat preheated and additionally serves to cool the casing 12.

What is claimed is:

1. In apparatus for .forming and burning self-sustaining mixtures of fuel gas and air, the combination of a combustion tunnel having a relatively restricted throat at its inlet end, an entraining tube set to discharge into said throat across an .intervening ar gap, a jet orifice nozzle set to discharge into said tube across an intervenim air gap, means for supplying fuel gas to sai nozzle, a plurality of burners adapted to burn self-sustaining mixtures of fuel gas and air and set to discharge across the first mentioned air gap from points on opposite sides of the axis of the entraining tube in advance of the gap, and means for supplying a self-sustaining mixture of fuel gas and air' to said burners.

2. In apparatus for forming and burning self-sustaining mixtures of fuel gas and air, the combination of a combustion' tunnel hav-. ing a relatively restricted throat at its inlet end, an entraining tube set to discharge into said throat across an intervening au' gap, a jet orifice nozzle set to discharge into said tube across an intervening air gap, means for supplying fuel gas to said nozzle, a plurality of burners adapted to burn selfsustaining mixtures of fuel gas and air and set to discharge across the first mentioned air gap from points on opposte sides of the axis of the entraining tube in advance of the gap, means for supplying a self-sustaining mixture of fuel gas and air to said burners, and means adapted to close oflt' the air through' said throat.

3. In apparatus for forming and burning self -sustaining mixtures of fuel gas and air, 'the combination of a combustion tunnel having a relatively restricted throat at its inlet end, an entraining tube set to discharge into said throat across an intervening air gap, a jet orifice nozzle set to discharge into said tube across an intervening air ga means for supplying fuel gas to said nozz e, a burner adapted 'to burn a self-sustaining mixture of fuel gas and air positioned laterally of the entraining tube intermediate between said gaps and set to discharge into said throat, and means for supplyin a self-sustainng mixture of fuel gas 'an air to said burner.

4. In a paratus for forming and burning self-sustaning mixtures of fuel gas and air, the combination of a combustion tunnel having a relatively restricted throat at its inlet end, an entraining tube set to discharge into said throat across an intervening air gap, a jet orifice nozzle set to discharge into said tube across an intervening air gap, means for air gap, said chamber having an air inlet and supplying fuel gas to said nozzle, unitary supplying air to both of said ar ga s. i means common to both air gaps for cutting In testimony whereof I aflix my sgnature.

'off air supply thereto, and means for burning in front of said threat in a manner to allow the combustion products resulting from such burningto enter said tunnel.

5. In appaatus for forming and burning m self-sustaining mixtures of fuel gas and air, V the combination of means formng a Cham: be'r having an inlet for air, a combustion' tunnel communicating with said chamber, an entraining tube within the chamber set v u to discharge into said tunnel across an intervening air gap, a jet orifice nozzle within the chamber set to discharge into said tube across an intervening air gap, means for supplying fuel gas to said nozzle, and uni- 20 tary means adapted to close said chamber inlet to cut ofl' the air supply to both of said. air gaps. v

6. In a paratus -for forming and burning self-sustaning mixtures of uel gas and air, 25 the combination of'means forming a chamber having an inlet for air, a combustion tunnel-communicating with said chamber, an entraining tube within the chamber set to I discharge into said tunnel across an interg 30 vening air gap, ajet orifice nozzle within the chamber set to discharge ?into said tube across an intervening air gap, means for supplying fuel gas to said nozzle, means within said chamber adapted to burn' a self- V V 35 sustaining mixture of fuel gas and air in a l mo manner to discharge the burning mixture izto said tunnel, and means for-supplying a self-sustaining mixture of fuel gas and air to said means.

7. Inapparatus for forming and burning I I self-sustaining mixtures of fuel gas and air,

the combination of means forming a chamber .having an inlet for air, a combustion tunnel communicating with said chamber, an

a self-sustaining mixture of fuel gas and air i e WILLIAM M HEPBURN. 70

45 entraining tube within the chamber set to discharge into said tunnel across aninterveningair gap, ajet orifice nozzle within the 'chamber to set to discharge-into said tube v 50 across an intervening 'air gap, means for supplying fuel gas to said nozzle, and means within the chamber for imparting heat to the incoming air. i

8. In apparatus for forming and burning 55 self-sustaining mixtures of fuel gas and air,

the combination of a 'iurnace having a recess in its wall with a combustion tunnel leading from said recess to the interior of the furnace, means defining a chamber within said recess,-an entraining tube within said chamber set to discharge into said tunnel across an intervening air gap, and a jet orifice nozzle within said chamber set to discharge into said tube across an intervem'ng 4 .36 

